Zero Ge! Reductions of an N‐heterocyclic carbene (NHC) adduct of GeCl2 with magnesium(I) dimers afford a dimeric compound (see picture), which structural and theoretical studies show to contain a singlet digermanium(0) fragment :GeGe: datively coordinated by two NHC ligands.

Reduction of an N-heterocyclic carbene (NHC) adduct of SnCl(2), viz. [(IPr)SnCl(2)] (IPr = :C{N(Dip)C(H)}(2); Dip = 2,6-diisopropylphenyl), with a magnesium(I) dimer, has afforded the first NHC complex of a row 5 element in its diatomic form, [(IPr)Sn=Sn(IPr)]; a computational analysis of the complex indicates that it comprises a singlet state, doubly bonded tin(0) fragment, :Sn=Sn:, datively bonded by two NHC ligands.

Reactions of [Pt(PCy(3))(2)] (Cy = cyclohexyl) with group 12 metal dihalides have afforded the novel metal only Lewis pair (MOLP) complexes, [(Cy(3)P)(2)Pt→MX(2)] (M = Zn or Cd, X = Br or I), or the oxidative addition product, trans-[(Cy(3)P)(2)(I)PtHgI]. The zinc complex represents the first MOLP to contain an unsupported Pt→Zn linkage.

Germanium und sonst nichts! Die Reduktion eines Addukts aus einem N‐heterocyclischen Carben (NHC) und GeCl2 mit Magnesium(I)‐Dimeren ergab eine dimere Verbindung (siehe Bild), die nach Strukturuntersuchungen und theoretischen Studien ein Singulett‐Digermanium(0)‐Fragment :GeGe: enthält, das dativ durch zwei NHC‐Liganden koordiniert ist.

Reactions of the expanded ring N-heterocyclic carbene, 6-Dip (:C{N(Dip)CH2}2CH2, Dip = 2,6-diisopropylphenyl), with group 15 element trichlorides have yielded the monomeric complexes, [(6-Dip)ECl3] (E = P, As or Sb), two examples of which (E = P and Sb) have been crystallographically characterised. Reduction of [(6-Dip)PCl3] with KC8 yielded the unusual tetraphosphorus dicationic complex, [(6-Dip)2(μ-P4)]Cl2, the X-ray crystal structure of which shows it to be an ion-separate salt. The compound can also be prepared from the direct reaction of excess 6-Dip with PCl3. Treatment of the cyclic amidinium salt, [6-MesH]Br (6-MesH = [HC{N(Mes)CH2}2CH2](+), Mes = mesityl) with KC8, leads to reductive coupling of the heterocycle and formation of the hindered bis(hexahydropyrimidine), (6-MesH)2. An X-ray crystallographic analysis of (6-MesH)2 shows the compound to have a long central C-C bond, while an electrochemical analysis reveals it to undergo an irreversible two-electron oxidation in dichloromethane solutions.

Thermal rearrangement of the 1,2-bis(silylene), [{(4-ButPh)C(NDip)2}Si−]2 (Dip = 2,6-diisopropylphenyl, leads to the silyl-silylene, {(4-ButPh)C(NDip)2}Si−Si(H) {N(Dip)C(=NDip)(4-ButPh-H)}, via an intramolecular C−H activation reaction. The X-ray crystal structure, and limited spectroscopic data, for the compound are reported. The structure of the silyl-silylene incorporates an exocyclic imine fragment, which is unprecedented for this compound class.

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